Sheet-edge-forming device



June 24, 1930. REECE 1,767,094 srmm EDGE FORMING DEVICE Filed Sept. 17 1925 T 4 INVERTER- 1 c/oaeph/iPeece.

V ATTORNEY.

Patented June 24, 1930 UNITED STATES PATENT QFFEE JOSEPH A. REECE, OF TOLEDO, OHIO, ASSIGNOR TO LIBBEY-OWENS-GLASS COMPANY,

OF TOLEDO, OHIO, A CORPORATION OF OHIO SHEET-EDGE-FORMING DEVICE Application filed September 17, 1925. Serial No. 56,834.

The present invention relates to sheet glass apparatus, and has particular reference to an improved form of sheet width maintaining device.

An important object of the present invention is to provide a means for creating relative speeds simultaneously within the edges of the glass sheet.

Another object ofthe present invention is 10 to provide means for partially relieving the stress in the sheet edges, and at the same time create a condition in the edges to overcome the narrowing tendency of the sheet when out of engagement with said means.

Still another object of the invention is to reduce the amount of waste glass at the sheet edges to a minimum, and increase the net width of the sheet. y I

Other objects and advantages of the invention will become apparent during the course of the folllowing description.

In drawing a sheet of glass vertically from a mass of molten glass there is a tendency upon the part of the sheet to narrow and unless means are provided to overcome such a tendency the sheet will soon pull to a string or thread at its source. Such means are set forth in the patents to Golburn, 1,248,809, and Henshaw, 1,460,582, consisting of a pair of suitably rotating knurled rolls engaging the sheet edges at the source thereof, which have proved commercially successful. After the sheet has been formed and annealed, the edges formed by the knurled rolls are cut off and later used for cullet.

It is an improvement upon such ameans to which the present invention refers.

In the drawings wherein like numerals are employed to designate like parts throughout the same Fig. 1 is a transverse vertical section through a sheet glass drawing apparatus, showing the improved edge rolls in elevation.

Fig. 2 is an enlarged sectional plan on the line 22 of Fig. 1, showing the improved edge rolls in position.

Fig. 3 is a full-size section of the final sheet edge, and

Fig. 4 is a fragmental sectional elevation fiected into the horizontal over the bending roll 7. The numeral 8 refers to substantially the same drive and drive connections and supporting means for the improved width maintaining rolls 9, as employed by the Colburn and Henshaw patents men tioned above, so it is not deemed necessary to further describe the same here as the details thereof do not form a part of the present invention.

It is to be understood that the improved form of width maintaining device is not limited to the Well-known Colburn process of drawing sheet glass, but may be used in connection with most any sheet glass drawin process.

The rolls 9 are substantially in the form of spools, the center portions 10 thereof being smaller in diameter than their flanged ends 11 and 12. The flanged ends 11 and 12 are preferably knurled at their peripheries which afford a better contacting surface for gripping the glass engaging therewith. These rolls are mounted in the usual manner on the end of rotating hollow shafts 13. A. cooling fluid is circulated through the shafts and rolls by means of a pipe 14 therein in order to prevent the rolls from oxidizing, and also to chill the sheet edges passing therebetween.

At the base of the sheet 6 and extending the full width thereof forms what is known in the art as a meniscus 1.5. It is in this meniscus at the'edge portions 16 of the sheet that these rolls are placed as clearly shown in Fig. 2. The knurled flanges 11 and 12 of the rolls are forced to bite into the meniscus (greatly reducing the thickness thereof) at the points 17 and 18. This biting force is caused by the spring pressure exerted at the drive end of the roll shafts 13 when the rolls are thrown into operating engagement with the sheet edges. As a result of the reduced diameters 10 of the rolls 9, a bulged portion 19 in the sheet ed e is formed which is substantially equa in thickness to the natural meniscus 20 formed at the base of the main body portion of the sheet and is greater in thickness than the portions 17 and 18. This bul ed portion 19 is locked or keyed bet-ween the coacting knurled flanges 11 and 12 of the edge rolls 9.

As pointed out in the Colburn and Henshaw patents, these edge rolls are driven at a lower rate of speed than the speed at which the glass is drawn from the draw pot, the purpose of this slower speed being to produce tension in the edges. The edges then become relatively stiff owing to the tension created therein by the slower speed and also from being chilled by passing between the cooled edge rolls. The purpose of the stiff edges is to prevent the formation of vertical waves in the sheet as well as the narrowing thereof during the drawing operation. The rolls referred to in these patents also serve as a means for feeding the glass from the draw pot to the sheet edges. It is'obvious from the above that the main body of the sheet travels at a greater speed than the edges at the source. It is the opinion that the retarded speed of the stiff sheet edges, when turned loose from their edge rolls, and the speed of the main body portion of the sheet cannot satisfactorily synchronize with one another in such an abrupt manner, the result being a slight narrowing of the sheet at a point just above the edge rolls. In other words, the retarded sheet edges tend to creep toward the part of the glass sheet having the greatest speed.

Vith the improved form of edge rolls covered by this invention the central portion thereof having reduced diameters 10, will permit the portion 19 of the sheet edge meniscus to substantially conform thereto. Portion 19 of the sheet edge meniscus will then be only slightly subjected to the biting action of the rolls, the actual gripping of the sheet edge 16 being accentuated upon by the knurled flanges 11 and 12 at the points 17 and 18'. The same relative speeds can be substantially maintained as referred to in the Colburn and Henshaw patents or it may be found that other speed ratios will prove satisfactory. The portion 19 of the sheet edge meniscus being only slightly gripped by the reduced diameters of the edge rolls, travels at a little greater speed than at the adjacent tightly gripped portions 17 and 18. This greater speed prevails because the resistance offered by the edge rolls at their smaller diameter is not ontirely sufficient to overcome the greater drawing force and speed of the drawing mechanism. The gripping of the flanges 11 and 12 into the edge meniscus at the points l7 and 18, together with the chilling action of the entire edge rolls and the relatively slow peripheral speed thereof, is sufficient to create the necessary rigidity in the sheet edges. Owing to the fact that the speed of the sheet edge portion .19 between the flanges 11 and 12 is substantially equal to the speed of the main sheet body in the proximity of the flanges 12, there will be less tendency on the part of the sheet edges, after leaving the rolls, to creep in toward the sheet center.

The same procedure is necessary in drawing the glass with the improved edge rolls as set forth in the Colburn and Henshaw patents. Portion 19 of the sheet meniscus, after leaving the improved edge rolls, will draw to thickness somewhat in the same manner as the main sheet meniscus 20 does.

As referred to by the numeral 21 in Fig. 3, portion 19 will probably drawn in the manner as illustrated, slightly thicker than the main sheet portion 22 owing to the chilling action of the rolls. This thicker portion 21 is desirable as it provides for a stiff sheet edge, necessary during the vertical run of the sheet.

It is believed that this improved form of edge roll will further eliminate the narrow ing or contracting tendency of the sheet at its source, and will also reduce the volume of the glass in the wasted sheet edges.

It is to be understood that the form of the invention herewith shown and described is to be takenas the preferred embodiment of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Claims:

1. In sheet glass apparatus, means for drawing a sheet from a mass of molten glass, including a roll adapted for engagement with the sheet edge, said roll having a smaller circumference'at its center than at its ends.

2. In sheet glass apparatus, means for drawing a sheet from a mass of molten glass, including pairs of rolls, having smaller circumferences at their centers than at their ends, engaging the respective sheet edges.

3. A sheet glass width maintaining device. comprising rotating rolls engaging the sheet edges and flanged ends on the rolls, looking a portion of the sheet edges therebetween.

1; A sheet glass width maintaining device, including rolls engaging the sheet edges and flanged ends on the rolls extending radially thereof and having knurled or roughened peripheries.

5. In sheet glass apparatus, means for drawing a sheet from a sheet supplying meniscus formed on a mass of molten glass, rolls engaging the meniscus near the edges each side of the thereof only, a portion of the rolls conforming substantially to the natural curvature of the meniscus, and other portions ofsard rolls being shaped to reduce the meniscus thickness when the rolls are arranged 1n operative association.

6. In sheet glass apparatus, means for drawing a sheet from a sheet supplying meniscus formed on a mass of molten glass, means engaging the edges of the meniscus for holding the sheet to width, consisting ofv pairs of rotating rolls and flanges on the ends of the rolls extending radially thereof and which bite into the meniscus.

7. In a sheet glass apparatus, means for drawing a sheet from a sheet supplying meniscus formed on a mass of molten glass, rotating flanged rolls engaging the meniscus edges, the flanges reducing the meniscus thickness and forming a bulged portion adj acent the reduced thickness.

8. In sheet glass apparatus, means for drawing a sheet from a sheet supplying meniscus formed on a mass of molten glass, rolls engaging the meniscusedges, flanges on the ends of the rolls, locking a portion of the meniscus therebetween to prevent the narrowing of the meniscus.

9. The process of producing sheet glass, consisting in drawing a sheet from a mass of molten glass, in forming an edge at each side of the sheet by gripping the sheet at spaced points adjacent each edge thereof, and in also gripping the sheet between the spaced points but to a less degree.

10. The process of producing sheet consisting in drawing a sheet from a of molten glass,

glass, mass in forming an edge at each side of the sheet by applying tension to the sheet at spaced points adjacent each edge thereof, and in also applying tension to the sheet between the spaced points but to a less degree.

11. The process of producing sheet glass. consisting in drawing a sheet from a mass of molten glass, and in forming an edge at sheet having a relatively thick central portion and two relatively thinner side portions by gripping and compressing the sheet at spaced points adjacent each edge thereof.

12. The process of producing sheet glass, consisting in drawing a sheet from a mass of molten glass, in forming an edge at each side of the sheet having a relatively thick central portion and two relatively thinner side portions by gripping and compressing the sheet at spaced points adjacent each edge thereof, and in also gripping and compress ing the sheet between the spaced points but to a. less degree.

Signed at Toledo, in the county of Lucas, and State of Ohio, this 15th day of September, 1925.

JOSEPH A. REEOE. 

